You should be good at fire and maneuver tactics. Find cover and clear your side.
Sidestep and fire at anything that aren't human. wipe out the grunts first, the less guns
firing at you at one time the better. When attacking an Elite it usually works to charge
him, unloading as much ammunition at him as possible and then hitting him with the
weapon. Try charging Jackals also. Go straight at a group of them and beat the first
one you come to with your weapon. The rest usually scatter and you can shoot them
in the back. (Dishonorable? Screw that! Survival!)